Thank you for the quick answer. I realize re-reading my question I accidentally deleted a key piece of information from what I had originally typed. His final paystub shows YTD overtime of $3,147. 

I can't account for the fact that box 14 amount is $1,835, but if I calculate the 50% premium based on his YTD overtime total of $3,147, it seems like the OT premium amount should only be $1,049. I'm not sure where the extra $786 in box 14 is coming from, unless some of those holiday/sunday hours were also overtime hours that just aren't stated that way on the pay stub.